Always very accurate predictors of what is happening in a battery 

July 13 [Sat], 2013, 10:14
Particularly important for electric vehicles is the ability to accurately predict how much charge is left in a battery at any given time, also known as its state-of-charge. In most automobiles, fuel gauges monitor the amount of gas remaining in the tank and drivers know to fill up when the gauge approaches empty. Similarly, in an electric vehicle, a state-of-charge monitor plays the role of a fuel gauge and lets 12 cells Satellite P775 the driver know how much charge is left in the battery. No one wants to be stranded miles away from a charging station, so researchers attempt to ensure the most accurate state-of-charge readings in electric vehicles.

A research team from North Carolina State University led by Dr. Mo-Yuen Chow and his PhD student Habiballah Rahimi-Eichi recently devised a system to more reliably determine the amount of charge remaining in a lithium-ion battery, like those used in plug-in electric cars. You may have noticed that battery monitors, like those on cell phones, tend to become less reliable as the battery ages.

That's because a battery's ability to hold charge depends on several factors that vary with time — the age of the battery, its temperature, and the rate at which the battery was charged, for example. Most battery monitoring systems do not take all of these factors into account; instead, they rely on measurements of the battery's voltage or current, which are not always very accurate predictors of what is happening in a battery.

A battery's state-of-charge cannot be directly measured, so researchers have been developing models that predict state-of-charge using a number of input variables. Unlike other models, Chow and Rahimi-Eichi's model relies on12 cells Satellite P775D software that incorporates data from a battery's voltage and current readings, in addition to its charging/discharging rate, age, and temperature in real time and feeds them into a program that predicts the state-of-charge. The team's model yields a prediction that is accurate to within 5 percent, and it is easier to implement than similarly accurate models.

Creating batteries that can charge for a later use 

July 13 [Sat], 2013, 10:08
Batteries tend to stay in the background until we run into a problem — like a dead car battery stranding us in the middle of nowhere or a 12 cells Satellite P770 faulty cell phone battery tying us to an outlet. Despite this, many exciting, promising developments have recently stemmed from cutting-edge battery research

Technologies big and small have increased demand for more efficient batteries. Smaller gadgets, such as cell phones and tablets, require powerful batteries at the smallest size possible. Meanwhile, larger, more environmentally friendly vehicles require batteries that can compete with their internal combustion cousins. Creating batteries that can charge for a later use, power a device at the push of a button, recharge quickly and regularly, and be tailored to match the design and needs of different technologies requires a great deal of development work.

Scientists around the world are engaged in many different aspects of battery research, ranging from improving their durability and lifetime to optimizing them for integrating renewable energy systems (like solar and wind) into the12 cells Satellite P770D electrical grid.

There are groups working on new kinds of batteries that can store more charge for longer periods of time than the most efficient lithium-ion batteries, and other groups are working on techniques for charging batteries more rapidly. As hybrid and fully electric vehicles become increasingly popular, research related to optimizing electric vehicle battery technology has already taken off.

Power consumption of a laptop depends upon all of the components  

July 12 [Fri], 2013, 16:50
There are to things that will be the basis for determining how long a laptop computer should run on batteries. Of course, the overall capacity of the battery is the easiest to determine and understand. All batteries can store a fixed amount of energy in them. This is rated in mAh or milliampere-hours. I could go into12 cells Satellite A655 technical details but suffice to say, the higher the mAh that a battery is rated out, the more energy that is stored in the battery.

So, why is the battery capacity important? Of two systems that use the same amount of power, the one with a higher mAh rated battery will last longer. This makes comparison easy for the batteries themselves. The problem is that no two laptop configurations will draw the same amount of power.

Power consumption of a laptop depends upon all of the components that make up the system. So, a system with a lower power consumption CPU will generally last longer if all parts are equal but they almost never are. It gets even more complicated because the power consumption can also vary depending upon12 cells Satellite A660 how the laptop is being used. Heavy disk uses draws more power than little usage.

All isn't lost for consumers though. In general the size of the laptop will also equate to how much power it uses. For example, a desktop replacement will generally draw more power than a thin and light. A thin and light draws more power than an ultraportable and a netbook draws even less still.

The tech and electric vehicle industries depend on batteries 

May 24 [Fri], 2013, 11:51
The company is relying on a buyer for its battery maker, A123 Systems, which filed for bankruptcy earlier this year and is up for AS10D75 compatibleauction next week, with companies like Johnson Controls (NYSE: JCI) and Wanxiang vying for ownership.

But Fisker only has a limited supply of electric vehicles, and it will run out of its product by spring if buyers don't come through.

It's not alone in the problems caused by A123's bankruptcy; the battery company also supplied companies like GM (NYSE: GM), which just this week debuted its new electric vehicle: the Chevy Spark.

A spokesman for GM told USA Today the car would maintain production levels, but there's no denying this incident is an example of a larger problem.
The tech and electric vehicle industries depend on batteries. And consumers are constantly demanding improvements, particularly in three categories: longer life, more power, and faster charging.

When it comes to electric vehicles, longer battery life is in high demand. Since EV charging infrastructure is few and far between, drivers want their EV to go further on one charge. Fifty miles will no longer cut it. 150 and up is more like it.

And charging time is another issue with these vehicles. No one has six hours to wait for a charge in the middle of a road trip. Companies that have that half hour-long – or even hour-long – charging technologies are going to be the winners.

This is why the Department of Energy has decided to take matters into its own hands. The Department announced today that it would be opening a battery and energy storage research facility at the Argonne National Laboratory in Lemont, Illinois, investing $120 million in the venture over five years.

When Energy Secretary Steven Chu took office, he came up with a plan for what he called “innovation hubs,” where research would take place for energy advancement.
Out of the eight he had originally AL10C31 compatibleproposed, five have been approved by Congress and only three are in operation, according to the New York Times.

The three currently operating include a lab for energy efficient building designs, one for fuels from sunlight, and one for light-water nuclear reactors.

4

The secret lies in Argonne's silicon carbide battery anode material 

May 24 [Fri], 2013, 11:48
Energy storage specialist California Lithium Battery (CLBattery) has announced that it has begun work to commercialise a third-generation lithium-ion battery based on technology created at the Argonne National AL10D56 compatible Laboratory. The result: a battery which promises to last three times as long as anything else on the market.

The secret lies in Argonne's silicon carbide battery anode material, which replaces the graphite anode traditionally used in lithium-ion batteries. While silicon carbide had previously been discounted for use in lithium-ion batteries due to its instability, Argonne researchers discovered that applying graphene to the anode - a process it calls graphitisation - resulted in a material with twice the lithium-ion capacity of graphite alone.

Using graphitised silicon carbide as an anode, Argonne claims, results in a direct reduction in weight of the combined anode and cathode by 16 per cent - or, alternatively, an increase in capacity for the same weight. The technology promises to scale with future battery technologies, too, up to a potential 50 per cent weight reduction.

Sadly, while CLBattery is forging ahead with a commercial implementation, it's going to be a while before your laptop or smartphone sees the benefit. The company's first product built around the technology is designed for AS10D41 compatibleuse in grid energy storage and electric vehicle applications.

Following the technology's release over the next two years, however, it's likely that Argonne will be looking to licence its invention to other manufacturers - including gadget makers. With the promise of increased longevity and a choice of reduced weight or boosted capacity, it could well prove the first real success for the miraculous graphene.

Exposing the battery to undue overcharge on a long drive 

March 30 [Sat], 2013, 11:13
AGM technology was developed in 1985 for military aircraft to reduce weight, increase power handling and improve reliability. The acid is absorbed by a very fine fiberglass mat, making the battery spill-proof. This enables 12 cells Aspire 5741shipment without hazardous material restrictions. The plates can be made flat to resemble a standard flooded lead acid pack in a rectangular case; they can also be wound into a cylindrical cell.

AGM has very low internal resistance, is capable to deliver high currents on demand and offers a relatively long service life, even when deep-cycled. AGM is maintenance free, provides good electrical reliability and is lighter than the flooded lead acid type. It stands up well to low temperatures and has a low self-discharge. The leading advantages are a charge that is up to five times faster than the flooded version, and the ability to deep cycle. AGM offers a depth-of-discharge of 80 percent; the flooded, on the other hand, is specified at 50 percent DoD to attain the same cycle life. The negatives are slightly lower specific energy and higher manufacturing costs that the flooded. AGM has a sweet spot in midsize packs from 30 to 100Ah and is less suitable for large UPS system.

AGM batteries are commonly built to size and are found in high-end vehicles to run power-hungry accessories such as heated seats, steering wheels, mirrors and windshields. NASCAR and other auto racing leagues choose AGM products because they are vibration resistant. AGM is the preferred battery for upscale motorcycles. Being sealed, AGM reduces acid spilling in an accident, lowers the weight for the same performance and allows installation at odd angles. Because of good performance at cold temperatures, AGM batteries are also used for marine, motor home and robotic applications.

Ever since Cadillac introduced the electric starter motor in 1912, lead acid became the natural choice to crank the engine. The classic flooded type is, however, not robust enough for the start-stop function and most batteries in a micro-hybrid car are AGM. Repeated cycling of a regular flooded type causes a sharp capacity fade after two years of use. See Heat, Loading and Battery Life.

As with all gelled and sealed units, AGM batteries are sensitive to overcharging. These batteries can be charged to 2.40V/cell (and higher) without problem; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages). Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell), and a direct replacement with a sealed unit could spell trouble by exposing the battery to undue overcharge on a long drive. See Charging Lead Acid.

AGM and other sealed batteries do not like heat and should be installed away from the engine compartment. Manufacturers recommend halting charge if the battery core reaches 49°C (120°F). While regular lead acid 12 cells Aspire 5551need a topping charge every six months to prevent the buildup of sulfation, AGM batteries are less prone to this and can sit in storage for longer before a charge becomes necessary. Table 1 spells out the advantages and limitations of AGM.

A lithium-based battery should not get warm in a charger  

March 30 [Sat], 2013, 11:12
The performance and longevity of rechargeable batteries are to a large extent governed by the quality of the charger. In a price-competitive world, battery chargers are often given low priority, especially as consumer products. Choosing a quality charger is important considering the cost of battery replacement and 12 cells Aspire 5750 the frustration poorly performing batteries create. The charger should serve as a quintessential master and guardian angel to protect the environment and save money by extending battery life.

There are two varieties of chargers: the personal chargers and the fleet chargers. For cell phones, laptops, tablets or digital cameras, manufacturers include personal chargers. These are made for one battery type, are economically priced and perform well when used for the application intended.

The fleet charger serves employees in a team environment and often has multiple bays. The original equipment manufacturer (OEM) sells the chargers and third parties also provide them. While the OEMs meet the basic requirements, third-party manufacturers often include special features, such as a discharge function for battery conditioning and calibration.
Some manufacturers of third-party chargers have become creative and offer advanced charge methods for lead- and nickel-based batteries. While pulse charging may be beneficial for nickel-based batteries, this method is not recommended for Li-ion. The voltage peaks are too high and cause havoc with the protection circuit. Battery manufacturers do not support alternative charging methods and say that pulse charging could shorten the life of Li-ion.

There are many valuable additional features for chargers, and hot- and cold-temperature protection is one. Below freezing, the charger lowers or prevents charge depending on the type of battery. When hot, the charger only engages when the battery temperature has normalized to a safe level. Advanced lead acid chargers offer temperature-controlled voltage thresholds, as well as adjustments to optimize charging for aging batteries.

Some chargers, including Cadex chargers, feature a wake-up feature or “boost” to allow charging Li-ion batteries that have fallen asleep. This can occur if a Li-ion battery is stored in a discharged condition and self-discharge has depressed the voltage to the cut-off point. Regular chargers read these batteries as unserviceable and the packs are discarded. The boost feature applies a small charge current to activate the protection circuit to 2.20–2.90V/ cell, at which point a normal charge commences. Caution should be applied not to boost lithium-based batteries back to life that have dwelled below 1.5V/cell for a week or longer.

There are two common charge methods, which are voltage limiting (VL) and current limiting (CL). Lead- and lithium-based chargers cap the voltage at a fixed threshold. When reaching the cut-off voltage, the battery begins to saturate and the current drops while receiving the remaining charge on its own timetable. Full charge detection occurs when the current drops to a designated level. Read more about Charging Lead Acid.

Nickel-based batteries, on the other hand, charge with a controlled current and the voltage is allowed to fluctuate freely. This can be compared to lifting a weight with an elastic band. The slight voltage drop after a steady rise indicates a fully charged battery. The voltage drop method works well in terminating the fast charge, however, the charger should include other safeguards to respond to anomalies such as shorted or mismatched cells. Most batteries and chargers also include temperature sensors to end the charge if the temperature exceeds a safe level. Read more about Charging Nickel-cadmium.

A temperature rise is normal, especially when nickel-based batteries move towards full-charge state. When in “ready” mode, the battery must cool down to room temperature. Heat causes stress and prolonged exposure to elevated temperature shortens battery life. If the temperature remains above ambient, the charger is not performing right and the battery should be removed when “ready” appears. Extended trickle charge also inflicts damage, and nickel-based batteries should not be left in the charger for more than a few days.

A lithium-based battery should not get warm in a charger and if this happens, the battery or charger might be faulty. Discontinue using the battery and/or charger. Li?ion chargers do not apply a trickle charge and disconnect the battery electrically when fully charged. If these packs are left in the charger for a few weeks, a recharge may occur when the open circuit voltage drops below a set threshold. It is not necessary to remove Li-ion from the charger when full; however, if not used for a week or more, it is better to remove them and recharge before use.

A mobile phone charger draws about 2 watts on charge, while a laptop on charge takes close to 100 watts. The standby current12 cells Aspire 5742 must be low and Energy Star offers mobile phone chargers drawing 30mW or less five stars for high efficiency; 30–150mW earns four stars, 150–250mW three stars, and 250–350mW two stars. The industry average is 300mW on no-load consumption and this gets one star; higher than 500mW earns no stars. Low standby wattage is only possible with small chargers, such as the four billion mobile phone chargers that are mostly plugged in.

Manufacturers are constantly improving lithium-ion 

January 25 [Fri], 2013, 10:28
Pioneer work with the lithium battery began in 1912 under G.N. Lewis but it was not until the early 1970s when the first non-rechargeable lithium batteries became commercially available. lithium is the lightest of all metals, has the replacement PA3634U-1BAS greatest electrochemical potential and provides the largest energy density for weight.

Attempts to develop rechargeable lithium batteries failed due to safety problems. Because of the inherent instability of lithium metal, especially during charging, research shifted to a non-metallic lithium battery using lithium ions. Although slightly lower in energy density than lithium metal, lithium-ion is safe, provided certain precautions are met when charging and discharging. In 1991, the Sony Corporation commercialized the first lithium-ion battery. Other manufacturers followed suit.

The energy density of lithium-ion is typically twice that of the standard nickel-cadmium. There is potential for higher energy densities. The load characteristics are reasonably good and behave similarly to nickel-cadmium in terms of discharge. The high cell voltage of 3.6 volts allows battery pack designs with only one cell. Most of today's mobile phones run on a single cell. A nickel-based pack would require three 1.2-volt cells connected in series.

Lithium-ion is a low maintenance battery, an advantage that most other chemistries cannot claim. There is no memory and no scheduled cycling is required to prolong the battery's life. In addition, the self-discharge is less than half compared to nickel-cadmium, making lithium-ion well suited for modern fuel gauge applications. lithium-ion cells cause little harm when disposed.

Despite its overall advantages, lithium-ion has its drawbacks. It is fragile and requires a protection circuit to maintain safe operation. Built into each pack, the protection circuit limits the peak voltage of each cell during charge and prevents the cell voltage from dropping too low on discharge. In addition, the cell temperature is monitored to prevent temperature extremes. The maximum charge and discharge current on most packs are is limited to between 1C and 2C. With these precautions in place, the possibility of metallic lithium plating occurring due to overcharge is virtually eliminated.

Aging is a concern with most lithium-ion batteries and many manufacturers remain silent about this issue. Some capacity deterioration is noticeable after one year, whether the battery is in use or not. The battery frequently fails after two or three years. It should be noted that other chemistries also have age-related degenerative effects. This is especially true for nickel-metal-hydride if exposed to high ambient temperatures. At the same time, lithium-ion packs are known to have served for five years in some applications.

Manufacturers are constantly improving lithium-ion. New and enhanced chemical combinations are introduced every six months or so. With such rapid progress, it is difficult to assess how well the revised battery will age.

Storage in a cool place slows the aging process of lithium-ion (and other chemistries). Manufacturers recommend storage temperatures of 15°C (59°F). In addition, the battery should be partially charged during storage. Thereplacement satellite A105 manufacturer recommends a 40% charge.

The most economical lithium-ion battery in terms of cost-to-energy ratio is the cylindrical 18650 (size is 18mm x 65.2mm). This cell is used for mobile computing and other applications that do not demand ultra-thin geometry. If a slim pack is required, the prismatic lithium-ion cell is the best choice. These cells come at a higher cost in terms of stored energy.

Compared with traditional lead acid batteries 

November 08 [Thu], 2012, 15:29
The research project, sponsored by REAPsystems, was led by MSc Sustainable Energy Technologies student, Yue Wu and his supervisors Dr Carlos Ponce de Leon, Professor Tom Markvart and Dr John Low (currently working at thecheap rn873 RM791 University's Research Institute for Industry, RIfI). The study looked specifically into the use of lithium batteries as an energy storage device in photovoltaic systems.

Student Yue Wu says, "Lead acid batteries are traditionally the energy storage device used for most photovoltaic systems. However, as an energy storage device, lithium batteries, especially the LiFePO4 batteries we used, have more favourable characteristics."

Data was collected by connecting a lithium iron phosphate battery to a photovoltaic system attached to one of the University's buildings, using a specifically designed battery management system supplied by REAPsystems.

Yue adds, "the research showed that the lithium battery has an energy efficiency of 95 per cent whereas the lead-acid batteries commonly used today only have around 80 per cent. The weight of the lithium batteries is lower and they have a longer life span than the lead-acid batteries reaching up to 1,600 charge/discharge cycles, meaning they would need to be replaced less frequently."

Although the battery will require further testing before being put into commercial photovoltaic systems the research has shown that the LiFePO4 battery has the potential to improve the efficiency of solar power systems and help to reduce the costs of both their installation and upkeep. Dr Carlos Ponce de replacement battery for Vostro 1310 batteryLeon and Dr. John Low now plan to take this project further with a new cohort of Masters students.

Dr Dennis Doerffel, founder of REAPsystems and former researcher at the University of Southampton, says: "For all kinds of energy source (renewable or non-renewable), the energy storage device -- such as a battery -- plays an important role in determining the energy utilisation. Compared with traditional lead acid batteries, LiFePO4 batteries are more efficient, have a longer lifetime, are lighter and cost less per unit. We can see the potential of this battery being used widely in photovoltaic application, and other renewable energy systems."

The cells in notebook batteries need to stay connected in order to maintain  

September 06 [Thu], 2012, 11:47
Have you ever wondered what's inside notebook batteries? Hopefully, you've resisted the temptation to crack the notebook battery open, since that not only voids any warranty you have, but can also be quite dangerous. Since our trained technicians have opened several notebook 11.1v 5200mah 9cells Pavilion dv4 batteryin the safety of our lab, we thought we should share what we found.

From the outside, notebook batteries appear to be one solid mass, but notebook batteries actually consist of three component parts covered by a plastic shell or wrapper. The largest "ingredient" by weight and volume are the energy cells that generate power, but you'll also find a small printed circuit board (PCB) that controls how the notebook battery cells are recharged, as well as the connector that interfaces with your notebook.

Most new notebook batteries consist of 6, 9 or 12 lithium ion cells, carefully matched together because of their identical impedance levels. (Impedance, which is measured in Ohms, is a fancy word for resistance.) The notebook battery cells are wired both in series and in parallel to provide the voltage and current flow required by your laptop.

In case you've forgotten, parallel connections result in no change to the overall voltage of the circuit, while series connections multiply the voltage by the number of cells. The diagram below illustrates the point. The top drawing shows a parallel connection of four 1.5 Volt cells, while the bottom drawing shows similar cells wired in series. (In this case 4 x 1.5 Volts = 6 Volts.)

The electrochemical characteristics of a Lithium Ion notebook battery dictate that an individual cell carries 3.6 V. That's why most notebook batteries have a voltage rating that is an even multiple of 3.6 - usually 10.8 or 14.4.

The cells in notebook batteries need to stay connected in order to maintain the flow of electricity. This requires the terminals on a notebook battery be soldered together. Many notebook battery manufacturers insert the connected cells into a plastic sleeve, which they then seal at the seams with a special ultrasound machine. Their goal is to keep the cells tightly and densely connected, since the notebook battery pack has to meet precise tolerances to fit inside your laptop.

At one end of the notebook battery pack is a small circuit board that electronically senses the charge and discharge levels, as well as the overall state of the notebook battery, i.e. how much charge is left. This component is absolutely critical to the notebook battery pack; without it the lithium ion cells cheap rn873 Pavilion dv6 batterywould overcharge and overheat.

Finally, there is a specially designed connector that provides pathways both for the electrons to flow out of (and back into) the notebook battery pack, as well as for the PCB to communicate with the laptop microprocessor.

When everything is packed snugly together inside a plastic casing, the manufacturer slaps a descriptive label on the outside and sends it off to the market.